In general, a fuel cell system is a power generating system which electrochemically converts chemical energy of fuel into electrical energy within a fuel cell stack without changing the chemical energy into heat by combustion.
The fuel cell system generally includes the fuel cell stack generating the electrical energy and a fuel supply system supplying a fuel (hydrogen) to the fuel cell stack. An air supply system supplies oxygen in air, which is an oxidizing agent necessary for an electrochemical reaction, to the fuel cell stack. A heat/water management system removes heat of the fuel cell stack to outside and controls an operation temperature of the fuel cell stack.
Through the aforementioned configuration, the fuel cell system generates electricity by the electrochemical reaction between hydrogen that is the fuel and oxygen in the air, and discharges the heat and water as reaction by-products.
A fuel cell system for a vehicle, which is an energy converting apparatus formed of a membrane-electrode assembly (hereinafter referred to as an “MEA”), comprises an electrode/catalyst layer attached to both sides of an electrolyte membrane for generating an electrochemical reaction. As hydrogen ions move, a gas diffusion layer (hereinafter referred to as a “GDL”) evenly distributes reaction gas and transmits generated electricity and a gasket and a fastening mechanism maintains a sealing property and an appropriate fastening pressure of the reaction gas and a coolant. A separator, in which the reaction gas and the coolant move, generates a current by a cell reaction when hydrogen and oxygen (air) are injected.
In a polymer solid electrolyte fuel cell, hydrogen is supplied to a positive electrode (also referred to as a “fuel electrode”), and oxygen (air) is supplied to a negative electrode (also referred to as an “air electrode” or an “oxygen electrode”).
The hydrogen supplied to the positive electrode is dissolved into hydrogen ions (protons, H+) and electrons (e−) by a catalyst of the electrode layer formed on both sides of the electrolyte membrane, and among them, only the hydrogen ions (protons, H+) selectively pass through the electrolyte membrane that is a positive ion exchange membrane and are transmitted to the negative electrode, and simultaneously, the electrons (e−) are transmitted to the negative electrode through the GDL that is a conductor and the separator.
A reaction occurs in the negative electrode in which the hydrogen ions supplied through the electrolyte membrane and the electrons transmitted through the separator react with the oxygen supplied to the negative electrode to generate water.
A current is generated by the electrons flowing through an external conductive wire as the hydrogen ions move, and heat is also generated in the water generation reaction.
In order to manufacture a fuel cell, a loading/unloading system for adsorbing a thin film sheet of a combination of the MEA and the GDL and moving the adsorbed thin film sheet has been applied.
An adsorption part adsorbs both upper sides of the thin film sheet for the fuel cell. A center portion of the thin film sheet, which is not adsorbed during a loading/unloading process, may droop to a lower side by gravity. Due to the drooping phenomenon, the entire thin film sheet may be separated or fall from the adsorption part to degrade quality of the fuel cell and production efficiency.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.